CN112335146A

CN112335146A - Device for detecting contact with an electrical conductor, method for detecting contact with an electrical conductor, insulation stripper provided with such a device

Info

Publication number: CN112335146A
Application number: CN201880094906.0A
Authority: CN
Inventors: 帕特里克·伯杰; 拉斐尔·德施勒; 迈克尔·约斯特
Original assignee: Schloynig AG
Current assignee: Schloynig AG
Priority date: 2018-07-11
Filing date: 2018-07-11
Publication date: 2021-02-05
Anticipated expiration: 2038-07-11
Also published as: KR102647605B1; US11196238B2; JP7288918B2; EP3821508B1; CN112335146B; HRP20231535T1; WO2020065366A1; US20210273427A1; EP3821508A1; JP2022500619A; KR20210031863A; RS64918B1

Abstract

The invention relates to a device for detecting contact with an electrical conductor using at least one electrically conductive means (2ra,2 rb). The device comprises a tool holder (1r) which is mounted so as to be rotatable about an axis of rotation (X), and a tool (2r) is arranged on the tool holder (1 r). The device also comprises an Electrical Conductor (ECB) and a rotor-side inductive element distributed over the electrical conductor (lr), a parallel resonant circuit comprising at least one rotor-side subcircuit (A) and at least one stator-side subcircuit (B), a fixed circuit arrangement (28) and a stator-side inductive element (L2). The rotor-side inductive element (LI) and the stator-side inductive element (L2) are arranged relative to each other such that the typical oscillation parameters (cp, Am, f) of the parallel resonant circuit can be measured independently of the rotational speed of the tool holder (lr). The invention further relates to an insulation stripping machine and a method for detecting contact of at least one electrically conductive tool with an electrical conductor.

Description

Device for detecting contact with an electrical conductor, method for detecting contact with an electrical conductor, insulation stripper provided with such a device

The invention relates to a device for detecting contact with an electrical conductor using at least one electrically conductive tool, a method for detecting contact with an electrical conductor using at least one electrically conductive tool, and an insulation stripping machine which is equipped with at least one such device for detecting contact with an electrical conductor using at least one electrically conductive tool, according to the independent claims.

As the requirements for cable quality in the automotive or aeronautical industry and the like are increasing, even minor damage on the conductor, such as scratches or cuts, are increasingly regarded as a risk, since such damage in combination with vibration and/or corrosion effects may lead to conductor breakage. Some proposals have therefore been made for detecting tool conductor contact in cable processing machines. In a cable stripper, the tool usually corresponds to a knife.

Various devices and methods for stripping the insulation of electrical conductors are known from the state of the art.

A rotary stripper for stripping at least one sheath from an electrical conductor is shown, for example, in EP 3163696 a 1. This is a device with a rotary cutting wire stripper. A rotary strippers are strippers in which a wire stripping blade rotates about the longitudinal axis of the conductor to be stripped.

From WO 2014/147596 a1, a device for detecting contact of a non-rotating tool as a wire stripper with an electrical conductor is known. In this device, the stripping blade is directly connected to the line device for the blade-conductor contact detection via an electrical conductor. This device is not suitable for known types of rotary stripping heads.

EP3121918a1 utilizes capacitive coupling for analog measurement signal transmission. There are a number of important limitations to this device. The concentric ring capacitors with air gaps must be realized very precisely mechanically, so that no inadmissible capacitance fluctuations occur during the stripping process, which can be interpreted as a contact error of the tool conductors. Another disadvantage of the capacitive coupling described in EP3121918a1 is that the large base capacitance of the fixed and moving device parts severely limits the sensitivity, and tool conductor detection is therefore difficult or impossible for short cables with small cross-sections.

The task of the present invention is to overcome one or more of the drawbacks of the state of the art. In particular, a device, a method and a stripping device for insulation layers which are as simple as possible, so that a contact with an electrical conductor to be stripped can be reliably detected by means of at least one electrical conductor tool. The object of the invention is to provide a rotary cutting stripper which allows simple and reliable stripping of the insulation of electrical conductors, in particular with a device for reliable and sensitive detection of contact of the conductors with a tool, so that damage to the electrical conductors is minimized and/or at least reliably indicated during stripping.

This object is solved by the devices and processes defined in the respective patent claims. Other embodiments are further described in the related patent claims.

The device according to the invention for detecting contact with an electrical conductor, in particular a conductor provided with a non-conductive sheath, by means of at least one electrically conductive tool rotating about the electrical conductor comprises a tool holder rotatably mounted about a rotational axis. Here and in the following, rotatably supported means that the tool holder can be rotated in any direction around the axis of rotation and at any angle of 0 to an unlimited number of degrees. Tools are mounted on the tool holder. The apparatus includes an electrical conductor disposed on the tool holder. The electric conductor mainly comprises a tool holder and a hollow shaft. The electrical conductor is electrically insulated from the tool, in particular by an electrical insulation layer. The device also comprises a rotor-side inductive element, which is arranged on the tool holder or on the hollow shaft, and a parallel resonant circuit, which comprises at least one rotor-side subcircuit and at least one stator-side subcircuit. The device comprises a circuit arrangement and a stator-side inductive element. The rotor-side inductance element is electrically connected to the tool, at least the conductor, via the electrical conductor. All these elements constitute the elements of the rotor-side subcircuit of the parallel resonant circuit. At least the stator-side inductive element is arranged in a stator-side subcircuit of the parallel resonant circuit. The stator-side and rotor-side inductive elements are inductively coupled to each other. The stator-side subcircuit of the parallel resonant circuit is connected to the circuit arrangement by an electrical conductor for detecting a change in at least one typical oscillation parameter, in particular the phase and/or phase shift of the parallel resonant circuit. The parallel resonant circuit has a total capacitance that functionally includes at least a tool capacitance. Depending on the circuit configuration, the total capacitance also includes the conductor capacitance of the electrical conductors of the rotor-side subcircuit and/or the conductor capacitance of the electrical conductors of the stator-side subcircuit and/or the output capacitance of the circuit arrangement and/or an additional rotor-side balancing capacitance. Other stray capacitances and parasitic capacitances may affect the total capacitance and must be considered. By a suitable selection of the electrical conductors and/or the additional output capacitance and/or the additional rotor-side balancing capacitance, the total capacitance can be set to a desired initial value, and the individual partial circuits can be coordinated with one another. In particular, it is advantageous to coordinate the resonant frequencies of the rotor-side and stator-side partial circuits when the coupling factor of the inductive element is low.

The rotor-side inductive element and the stator-side inductive element are arranged in a suitable manner, in particular spaced apart from one another and preferably not in contact, so that at least one of the typical oscillation parameters of the parallel resonant circuit can be measured independently or in a specific function as a function of the rotational speed of the tool holder relative to the circuit arrangement.

Typical oscillation parameters include, for example, amplitude, frequency and/or phase shift between the input signal and the output signal, such as between the frequency generator signal and the stator side resonant circuit signal.

The electrical conductor for connecting the tool may be a cable. However, it is also conceivable that it is only a conductor track, for example on a printed circuit board, or merely an electrical connection by soldering, plugging, riveting, pinning or screwing. If these electrical connections involve cables, they may be connected to the tool, for example by plugging or screwing through cable lugs.

At least the tool, the electrically insulating layer, the electrical conductor of the rotor-side subcircuit, together with its capacitance and the rotor-side inductive element belong to the rotor-side subcircuit elements. The elements of the stator side subcircuit mainly comprise a stator side inductance element, an electrical conductor of the stator side subcircuit, a capacitance of the electrical conductor and a circuit arrangement of the stator side subcircuit.

The individual components of the rotor-side partial circuit of the parallel resonant circuit are arranged on a rotatably mounted tool holder, and the individual components of the stator-side partial circuit of the parallel resonant circuit, in particular the stator-side inductive component and the fastening circuit, are arranged, preferably, on the fastening components of the insulation stripping machine.

The electrical conductor may comprise the entire tool holder. This means that the electrical conductor is identical to the tool holder. However, it is likewise conceivable for only a part of the tool holder to be designed as an electrical conductor and/or for the tool holder to be composed at least partially of an electrically non-conductive material. The non-conductive material comprises a ceramic, in particular an industrial ceramic or a plastic.

The tool holder and the electrical conductor may be designed as separate elements. For example, it is conceivable to design the electrical conductor only as a hollow shaft, ring or disc on the tool holder. It is likewise conceivable for the coating of at least one region of the tool holder to be designed as an electrical conductor.

For example, the electrical insulation between the tool and the electrical conductor can be designed as a film which at least partially surrounds the tool and provides insulation with respect to the tool holder which is already designed as an electrical conductor. The electrically insulating layer can also be designed as a separate element distributed between the tool and the electrical conductor. In addition, for tool holders which are already designed as electrical conductors, a non-conductive coating can also be provided for insulating purposes. In this case, it is conceivable to design the electrically insulating layer at least as part of the tool holder, in particular if only a part of the tool holder is designed as an electrical conductor, or if the electrical conductor is designed as a separate component, for example as a hollow shaft.

The electrically conductive tool, in combination with its surroundings, in particular the electrically insulating layer and the electrically conductive body, or according to different design variants together with the tool holder, forms a tool capacitance in the rotor-side partial circuit of the parallel resonant circuit.

The electrical conductor and the non-conductive sheath are typically provided as part of, or together as, a cable.

The arrangement of the rotor-side sub-circuit and the stator-side sub-circuit as described presently, which are coupled and form a parallel resonant circuit, enables the device to measure the oscillation parameters of the parallel resonant circuit independently of the rotational speed of the tool holder.

The tool or tools can be designed as cutters, in particular wire strippers. These tools are preferably two stripping knives opposite each other, which are of V-shaped design and overlap each other, in particular in the closed state. It is also contemplated that the oppositely located cutters each have straight cutting edges that are in close contact when the cutters are closed. More than two cutters are contemplated. It is conceivable to arrange a plurality of cutters in the form of variable diaphragms.

The rotor-side and stator-side inductive elements are preferably designed as coils, which are inductively coupled to one another.

The coil is a structural element that is easy to manufacture. By means of inductive coupling, the signals can be transmitted contactlessly.

By the contact of the tool with the conductor, the change in the characteristics, in particular the impedance of the rotor-side partial circuit, directly affects the entire parallel resonant circuit. In this way, by means of the typical oscillation parameters of the parallel resonant circuit, in particular the phase shift, a contactless evaluation of the rotor-side partial circuit can be carried out by means of the fixed circuit arrangement.

Inductive coupling within a parallel resonant circuit as presently described enables detection and transmission of a signal without having to perform complex modulation or conversion of the signal prior to or during inductive coupling.

The rotor-side and stator-side inductive elements may be arranged coaxially with the rotational axis of the tool holder and at least partially overlap.

The device can thus be produced compactly and the rotor-side and stator-side inductive elements can be reliably coordinated with one another.

The stator-side inductive elements can be designed as toroids. The rotor-side inductive element can be designed as a toroidal coil coaxial with the toroidal coil. These loop coils may partially overlap each other.

The toroidal coil can be easily produced with high accuracy.

Preferably completely overlapping toroids. This facilitates inductive coupling and enables a compact structure.

The rotor-side and stator-side inductive elements may be of cylindrical or plane-parallel design, coaxial with the axis of rotation of the tool holder. This allows the device to be manufactured in a configuration that is compatible with the corresponding stripper.

The rotor-side and/or stator-side inductive elements can be designed as spiral tracks of windings or electrical conductors on non-conductive and non-magnetic materials. The material is preferably plastic, such as POM, PEEK or FR 4. Thus, a low-cost and simple coil structure can be realized, and the plastic does not influence the magnetic field of the coil. Meanwhile, the design of the inductance element on the corresponding material also realizes the temperature-stable coupling.

It is also possible to select rotor-side and/or stator-side inductive elements with ferromagnetic material, in particular for improving the inductive coupling. The ferromagnetic material strengthens and guides the electromagnetic field, so that stronger coupling and inductance can be generated under the condition of the same structural size, and stray field is low, thereby obviously reducing the influence of the magnetic conductive machine part in the coil environment.

The rotor-side and/or stator-side inductive elements can be designed as single-layer coils. However, it is likewise conceivable to design the rotor-side and/or stator-side inductive elements as multilayer coils.

In this way, the required compact design and/or improved coupling can be achieved.

The tool may be embedded between two conductive plates. The conductive plate is electrically connected to the rotor-side inductance element through an electric conductor. They are furthermore electrically insulated from the electrical conductor, in particular by an electrically insulating layer. In this way, a connection can be established between the tool and the rotor-side inductive element.

It is likewise conceivable to connect the tool to the rotor-side inductive element via at least one electrical sliding contact and an electrical conductor. The electrical sliding contact can then consist of a conductive plate, a spring pin or an annular element. The tool is now electrically insulated from the electrical conductor. As an alternative, a simple electrical connection can likewise be established between the tool and the rotor-side inductive element in this way. In this way, the tool position, in particular the feed of the tool, can be changed by a linear or rotary motion.

Another aspect of the present invention relates to an insulation stripping machine equipped with at least one wire stripper as a tool. The stripping blade is held by a tool holder which is mounted so as to be rotatable about a rotational axis and to which at least one device for detecting contact with an electrical conductor of a cable, as described above, is connected. To this end, at least one tool is connected to the device.

In this way, a complete insulation stripping machine can be provided, in which the device for detecting contact with the electrical conductor is adjusted to the insulation stripping machine, and which takes into account specific machine parameters.

As is well known to the skilled person, the surroundings in the immediate vicinity of the parallel resonant circuit, i.e. the different components not belonging to the parallel resonant circuit itself, may influence the response of the parallel resonant circuit. This situation occurs when these peripheral elements of the parallel resonant circuit influence and change the electric and/or magnetic field of the parallel resonant circuit. With regard to the overall construction of the stripper, it must be ensured that the peripheral components do not influence stray electric fields or stray magnetic fields to an impermissible extent during operation of the stripper in order to prevent an impermissible detuning of the parallel resonant circuit. Detuning of the parallel resonant circuit can lead to detection errors, or changes in the sensitivity of the measurement system.

Another aspect of the invention relates to a method for detecting contact with an electrical conductor, in particular a conductor provided with a non-conductive sheath, by means of at least one electrically conductive tool rotating around the electrical conductor, using a device, in particular a device as described at the present time. The device comprises a tool holder rotatably supported about a rotational axis. Tools are mounted on the tool holder. The apparatus also includes an electrical conductor disposed on the tool holder. The electric conductor mainly comprises a tool holder and a hollow shaft. The device further comprises a rotor-side inductive element, a parallel resonant circuit, a fixed circuit arrangement and a stator-side inductive element. The tool is insulated from the electrical conductor by an electrically insulating layer. The rotor-side inductive element is arranged on the tool holder or on the hollow shaft. The parallel resonant circuit includes at least one rotor-side subcircuit and at least one stator-side subcircuit. The rotor-side inductance element is electrically connected to the tool, at least the conductor, via the electrical conductor. The rotor-side inductive element and the electrical conductor form an element of a rotor-side subcircuit of the parallel resonant circuit. At least the stator-side inductive element is arranged in a stator-side subcircuit of the parallel resonant circuit. The stator-side subcircuit of the parallel resonant circuit is connected to the circuit arrangement by means of an electrical conductor for detecting a change in at least one typical oscillation parameter, in particular a phase shift and/or a phase. The parallel resonant circuit has a total capacitance that functionally includes at least a tool capacitance. Depending on the circuit configuration, the total capacitance also includes the conductor capacitance of the electrical conductors of the rotor-side subcircuit and/or the conductor capacitance and/or the output capacitance of the electrical conductors of the stator-side subcircuit. Other parasitic capacitances may affect the total capacitance and therefore must be considered. By appropriate selection of the electrical conductors and/or the additional output capacitance, the total capacitance can be set to a desired initial value.

The method for detecting contact of a conductor of a tool at least comprises the following steps:

-setting the frequency generator signal in a range of the resonance frequency of the parallel resonant circuit, preferably below the resonance frequency of the parallel resonant circuit, according to the defined sensitivity

Measuring at least one oscillation parameter typical of a parallel resonant circuit, such as phase, frequency and amplitude, and determining a limit value for the contact of the tool with the conductor

-arranging a rotary tool holder relative to a stationary circuit

-at least continuously measuring the typical oscillation parameters, in particular the phase and/or the phase shift, of the parallel resonant circuit and continuously comparing these measured values with one or more limit values determined by means of standard measurements in order to detect a contact of the conductor with the tool.

The continuous measurement can be a continuous measurement or an intermittent measurement, i.e. a number of individual measurements, in particular a number of identical measurements, which are carried out at specific intervals over a certain period of time.

This method is typically part of the cable processing flow. In this way, the contact of the tool with the conductor can be detected without a galvanic connection being established between the tool and the circuit arrangement.

It is preferred that before the setting of the frequency generator signal, the resonance frequency of the parallel resonant circuit is determined by measuring the amplitude characteristic and/or the frequency characteristic in a frequency spectrum, which resonance frequency depends on the system and/or is empirically necessary to be in the frequency spectrum. If the frequency generator signal is set below the resonance frequency of the parallel resonant circuit, the frequency generator signal may be between 1% and 10%, mainly between 1% and 5%, preferably between 5% and 1%, depending on the specific application.

Preferably, after the tool holder begins to rotate, the tool is moved toward the conductor and cuts into the non-conductive sheath of the conductor. Preferably, a signal is output when a threshold value is reached or exceeded, by means of which at least one function of the stripper can be controlled.

The limit value can be a specified value starting from a higher value until below a lower value or starting from a lower value until a higher value is exceeded. For this purpose, the limit value can also be a deviation determined for a constant signal, and exceeding the last-mentioned limit value involves exceeding an allowable deviation from a reference value.

Of course, it is also possible to consider merely outputting a signal, for example for operating an alarm light or sending an alarm.

In this way, further stripping processes of the stripper, or other processes which are relevant to the control of the device, can be controlled and/or regulated, in particular stopping of the tool movement, moving the tool backwards, stopping of the rotary movement of the tool holder, etc.

In the stripping process, the conductor to be stripped is usually introduced between the tools in a first step. Once the conductor to be stripped is in position, it is fixed by means of suitable clamps, generally by means of centering clamps. It is likewise conceivable to initially fix the conductor to be stripped in a suitable holder and to introduce it between the tools via the holder. In the next step, the tools are preferably moved relative to each other and cut into or through the non-conductive sheath of the conductor.

One or more of the above-described processing steps of a typical wire stripping process are preferably combined or may be combined with the method for detecting conductor contact as presently described.

After the above steps, the conductive tool (preferably designed as a stripping blade) and the conductor are moved relative to each other along a rotational axis which generally coincides with the longitudinal axis of the conductor to be stripped, so that the cut sheath is stripped from the conductor. It is also conceivable to open the tool slightly before peeling, in particular if contact has been detected.

The jacket may be fully or partially peeled. In the case of partial stripping, the sheath remains on the electrical conductor, but is axially offset from its original position on the electrical conductor.

The measurement can also be continued while the sheath is being peeled off, so that contact of the tool with the electrical conductor can also be detected at this stage.

The circuit arrangement essentially evaluates the phase and/or the phase shift between the stator-side resonant circuit signal and the frequency generator signal.

A phase detector equipped with a simple tool can be used to evaluate the phase or phase shift, thereby providing a fast response in the event of contact between the tool and the electrical conductor.

During initialization, the frequency of the frequency generator is set slightly below the natural frequency of the resonant circuit, thereby advancing the resonant circuit relative to the frequency generator. But if the tool touches the electrical conductor to be processed, the resonant circuit will lag due to the additional capacitive load. Advancing or retarding the digital phase position can be powerful and fast. The difference between the natural frequency of the resonant circuit and the natural frequency of the frequency generator thus defines the sensitivity of the circuit arrangement.

The evaluation of the amplitude of the resonant circuit or the phase shift between the stator-side resonant circuit signal and the frequency generator signal or the combination thereof can likewise further improve the robustness or confidence check.

For this, it is conceivable to record the point in time at which the tool touches the conductor and the duration of time during which the tool touches the conductor as separate parameters.

This allows the depth of damage to the conductor to be accounted for when contact occurs, particularly when other time-dependent process data is included. The correspondingly processed conductors can thus be sorted. From the data obtained during the incision, in particular the depth of the conductor damage can be derived and/or the contact diameter can be determined and evaluated.

It is also conceivable to record the position of the tool in contact with the conductor in the direction of the axis of rotation in particular as a separate parameter.

This allows for an explanation of the location of conductor damage when contact occurs. The correspondingly processed conductors can thus be sorted. When the insulating layer is stripped from the conductor, the conductor damage length can be derived from the data obtained.

For which two or more parameters can be recorded and/or combined simultaneously.

With this information, the operator may define one or more exclusion criteria. If the damage is within an acceptable range, the processed conductor may still continue to be used.

This can also be explained for the following cases: the percentage of correctly performed stripping process, or in the stripped conductor, the percentage of occurrences or the likelihood of occurrence of damage, etc., and/or the severity of damage.

Furthermore, in this process, the position of the tool relative to the original position of the tool or relative to the axis of rotation can additionally or alternatively be recorded, in particular continuously, and compared with a reference value when the tool contacts a conductor. For this purpose, the diameter of the electrical conductor can be determined by means of a reference value for the diameter. But it is also advantageous to determine the depth of cut etc. of the tool in the conductor.

This facilitates, for example, the identification of the conductor by means of a test stripping at the beginning of the stripping process, so that parameters can be set for the machine. But also during operation. This may be required if the conductor diameter is subject to production fluctuations.

Due to manufacturing tolerances, the electrical conductors may be arranged different from the shaft of the non-conductive sheath within the non-conductive sheath. In other words, the thickness of the non-conductive jacket along the circumference of the conductor may vary. If an electrically insulated conductor with corresponding manufacturing tolerances is clamped in a clamp, the electrical conductor in the clamping device may not be located on the central axis in contrast. For the stripper this means that the electrical conductor is positioned eccentrically with respect to the axis of rotation.

It is also possible that due to manufacturing and assembly tolerances, the axis of rotation of the tool does not coincide with the central axis of the clamping device. For electrical conductors which are ideally manufactured completely coaxially, they are therefore likewise arranged eccentrically with respect to the axis of rotation.

During this process, particularly when cutting into the non-conductive sheath, the eccentricity vector and conductor diameter can be calculated using a tangential cutting method. The distance of the tool to the axis of rotation will additionally or alternatively be reduced until a first tangential contact with the conductor by the tool occurs. For which the angular position of the tool and the tool position can be saved. The position of the tool, in the present case the distance of the tool from the axis of rotation, now corresponds to the relevant first contact radius. In this way, for conductors arranged eccentrically with respect to the axis of rotation, the points furthest away from the axis of rotation, i.e. with respect to the radial distance to the axis of rotation and the polar angle, can be determined.

It is then preferred to further reduce the distance of the tool from the axis of rotation until the tool continues to contact the conductor during a complete revolution of the tool about the conductor. The position of the tool at this point, in the present case the radial distance of the tool from the axis of rotation, may be saved as the second contact radius. This allows the determination of the point on the conductor closest to the axis of rotation.

The eccentricity vector is preferably calculated based on the first and second contact radii and the angular position. The position of the longitudinal axis of the conductor can thus be calculated relative to the axis of rotation.

Crescent moon cutting is another common method for determining the eccentricity vector and the radius of the conductor. It will be preferred to reduce the distance of the tool from the axis of rotation until a first tangential contact with the conductor occurs through the tool. At least the radial position of the first tangential contact of the means is preserved, optionally together with the angle. In addition, the distance from the tool to the axis of rotation is also reduced to a crescent cutting radius until the tool contacts the conductor at the preferred crescent cutting angle of 120 ° to 200 °. The beginning of this contact is saved as the first crescent-shaped cutting contact angle, and the end of the contact is saved as the last crescent-shaped cutting contact angle.

First, the conductor radius, eccentricity, and eccentricity vector are calculated using the first contact radius, the crescent-shaped cutting radius, the first crescent-shaped cutting contact angle, and the last crescent-shaped cutting contact angle.

The position of the conductor relative to the axis of rotation can thus be determined.

In another step, the eccentricity vector may be used to move the conductor relative to the axis of rotation, thereby compensating for eccentricity. This means that the conductor axis is coaxial with the axis of rotation in the next process step.

As presently described, the method is preferably used in conjunction with a rotary cable strippers, particularly for coaxial, triaxial or single strand stranded cables.

The electrical conductor is preferably the conductive layer of a coaxial or triaxial cable. The steps described in the method may now be repeated for each layer of the coaxial or triaxial cable. In this way the diameter and/or eccentricity vector of the respective conductive layer can be determined.

In the method, it is likewise conceivable to record the point in time at which the tool touches the conductor and the duration of time during which the tool touches the conductor separately for each tool. This allows the conductor and/or the damage of the conductor to be determined/classified accurately.

It is also contemplated that a respective contact diameter may be calculated for each tool. Based on these calculated contact diameters, the tool can be adjusted radially with respect to the axis of rotation so that each tool is at the same distance from the longitudinal axis of the electrical conductor. Furthermore, it is possible to make adjustments to the tool during continuous operation, i.e. while the tool is rotating. It is also contemplated that the tools may be adjusted manually so that they are equidistant from the axis of rotation.

It is likewise conceivable with the present method to adjust the rotary shaft and the clamping device during assembly. For this purpose, the clamping device can be adjusted by means of an adjusting screw or an adjusting tool or the like according to the eccentricity vector and can then be fixed according to this adjustment.

By moving the clamping device with the actuator according to the eccentricity vector, active correction can likewise be carried out during the stripping process.

The invention will be explained in more detail below by means of examples of design. Illustration thereof:

FIG. 1 is a perspective view of an insulation stripper;

FIG. 2 is a cross-section taken along a rotation axis of the dielectric stripper;

FIG. 2b cross section of an alternative gauge in FIG. 2

Fig. 3 is a circuit diagram of a parallel resonant circuit with a circuit arrangement;

FIG. 4 is an equivalent circuit diagram of the parallel resonant circuit of FIG. 3;

fig. 5 is a circuit diagram of a phase detector;

fig. 6a to 6c are schematic flow charts of the wire stripping process.

FIGS. 7a to 7d are schematic diagrams of the flow of cross-sections through a conductor and correction of eccentricity

FIGS. 8a to 8b are schematic diagrams of the flow of the cross section through the conductor and the correction of the eccentricity

Fig. 1 shows a perspective view of a rotary dielectric stripper 100.

The insulation stripping machine 100 includes a stripping head 10 (see fig. 2) on which cutters 2ra and 2rb are arranged, a drive mechanism 20 for the stripping head 10, and a drive mechanism 30 for the cutters on the stripping head 10. The dielectric stripper 100 includes a frame 50 on which various components are disposed. The machine 100 includes means for detecting contact between at least one of the conductive tools 2ra,2rb (see fig. 2) and an electrical conductor, also referred to as a cutter conductor contact.

Fig. 2 shows in a schematic manner a cross section in the longitudinal direction along the rotation axis X of the rotary dielectric stripper 100 (see fig. 1). The present thread stripping head 10 is designed as a hollow body, is connected to the hollow shaft 6r and is mounted rotatably about the axis of rotation X. In the left-hand region of fig. 2, two cutters are provided as electrically conductive means 2ra,2rb, between which an electrical conductor 5b to be stripped is arranged. The electrical conductor 5b comprises a non-conductive sheath 5 a. The tools 2ra,2rb are mounted on the rotatable tool holder 1r so as to be radially movable. This means that the knives 2ra,2rb can be moved rotationally relative to each other about the axis X, thereby cutting through the non-conductive sheath 5a of the electrical conductor 5 b. The tools 2ra,2rb are insulated with respect to the tool holder 1r by an electrically insulating layer 40. The electrically insulating layer 40 here consists of two thin ceramic plates, each 0.5mm thick or the like, which surround the tool.

The present tool holder 1r is designed as an electrical conductor ECB. The rotor-side inductance element is arranged as a coil L1 on the hollow shaft 6 r. The current coil L1 is designed as a single-layer coil. The stator-side inductance element is arranged coaxially with the rotor-side inductance element. The present stator-side inductance element is also designed as a single-layer coil L2. One end of the rotor side coil L1 is connected to the two cutters 2ra and 2rb via an electric conductor 4 r. The connection of the conductor 4r to the cutters 2ra,2rb is now designed as a threaded connection. The second end of coil L1 is electrically connected to tool holder 1r and hollow shaft 6r, which together form current conductor ECB. These elements constitute a rotor-side subcircuit a of the parallel resonant circuit (see fig. 3 and 4). The ends of the stator side coil L2 are connected to the fixed circuit arrangement 28 by coaxial cables 4 s. The coil L2 is disposed on the fixed plate 51 as a part of the insulation stripper 100. This means that the stator side coil L2 is fixedly arranged. The rotor side coil L1 and the stator side coil L2 are arranged at an interval from each other.

The fixed circuit arrangement 28 comprises a frequency generator 3, a phase detector 7 and a series resistance Rv. The frequency generator 3 can be controlled or regulated by the control device 17 (see fig. 5) via the signal S5. The phase detector 7 detects the input signals U2s and U1. In addition, an output capacitor Ca is present on the fixed circuit arrangement 28. The circuit arrangement 28 can be communicated with via an interface COM.

Figure 2b shows a cross section of the alternative gauge of figure 2. Only the front part of the stripping head 10 is shown. For this purpose, the same reference numerals indicate the same elements as those described in fig. 2. To ensure simplicity, these are not repeated in the illustration of fig. 2b, and only the elements that differ with respect to fig. 2 are described. In fig. 2b, the tools 2ra and 2rb are likewise designed as cutters. They are each arranged between two electrically conductive plates 41, which are in turn arranged on an electrically insulating layer, which is designed as two

plates

40a and 40 b. The current tools 2ra and 2rb are not directly connected to the coil L1, but are only slidably connected to the conductive plate 41. The conductive plate is connected to the electric conductor 4r through the coil L1. The connection between the electrical conductor 4r and the conductive plate 41 is embodied as a soldered connection.

Fig. 3 shows in a schematic way a device for detecting contact between at least one rotating conductive tool 2r and an electrical conductor. The parallel resonance circuit is divided into an inductively coupled sub-circuit A and a sub-circuit B.

The parallel resonant circuit is preferably a high quality parallel resonant circuit. For this application, a high quality resonant circuit is typically a resonant circuit with a quality factor higher than 5.

C2r represents the tool capacitance, C4r represents the rotor side, and C4s represents the stator side cable capacitance. With the output capacitor Ca and the balancing capacitor Cm of the circuit arrangement 28, the resonance frequency of the entire resonance circuit can be adjusted, and the resonance frequencies of the partial circuits are preferably coordinated with one another or similarly selected.

In the present circuit diagram, the capacitance C5 represents the capacitance of the conductor 5b to be processed (see fig. 2 for this purpose).

The parallel resonant circuit is excited by the frequency generator 3 in combination with the frequency generator signal U1 with a series resistance Rv at a frequency below its resonant frequency. A control device 17 (see fig. 5), not shown here, controls the frequency generator 3 with an input signal S5 such that the parallel resonant circuit oscillates at a frequency below its resonant frequency when the tool is in the open state.

If one of the knives touches the electrical conductor 5b when cutting or stripping the insulation layer 5a, the capacitance C5 of the cable to be processed is connected in parallel with the resonance circuit capacitance Ct.

This increases the total capacitance Ct and the LC resonant circuit is detuned. This newly formed resonant frequency with the capacitance C5 is lower than the original resonant frequency of the parallel resonant circuit. For this purpose, at the fixed frequency of the frequency generator 3, a new phase shift occurs between the frequency generator signal U1 and the stator-side resonant circuit signal U2s, and a new amplitude value Am of U2 s. This phase shift is converted into an analog voltage U4 by the phase detector 7 and read by the control device or the like described above. A digital logic signal S4 (see fig. 5 for this purpose) may likewise be generated, which indicates whether the frequency generator signal U1 leads relative to the resonant circuit signal U2S. The signal S4 changes its value according to the different set frequencies of the frequency generator signal U1 and the additional capacitor C5. This is explained with reference to fig. 5.

Fig. 4 shows another schematic representation of the parallel resonant circuit of fig. 3. The coils L1 and L2, which are inductively coupled to each other in fig. 3, are represented by an equivalent circuit diagram of a coreless and lossless transformer.

Fig. 5 shows an embodiment of the phase detector 7. The phase detector has two

comparators

11 and 12. The XOR section 13 and the D-type flip-flop 16 are located downstream. As described in fig. 2, the parallel resonant circuit is preferably excited by the frequency generator 3 slightly below its resonant frequency. The frequency generator voltage is preferably sinusoidal.

The signals from the frequency generator U1 and the stator-side resonant circuit U2s are thus present at the input of the phase detector. These are converted by the

comparators

11 and 12 into rectangular signals S1 and S2, which are connected to each other by an XOR unit 13. At this time, a rectangular signal S3 is generated, the on-time and cycle time ratio of which is proportional to the phase shift between U1 and U2S. A low-pass filter 14 and an enhancer 15 are connected downstream of the XOR unit 13. The signal is filtered by a low pass filter 14 and enhanced by an enhancer 15. The analog signal U4 is finally read by the control device 17.

A D-type flip-flop 16 is arranged in parallel with this path. The rectangular signals S1 and S2 from the

comparators

11 and 12 are fed to the D-type flip-flop 16. D-type flip-flop 16 generates digital signal S4. If the square signal S2 is earlier than the square signal S1, then the signal S4 is a logic 1, otherwise the signal S4 is a logic 0, thereby indicating a tool conductor contact. By means of the signals U4 and S4, the control device 17 (which may also be part of the circuit arrangement 28) controls the frequency generator 3 such that the LC resonant circuit without conductor contact is preferably slightly below its natural resonant oscillation and responds sensitively to an increase in capacitance due to possible conductor contact.

Fig. 6a to 6c show a schematic flow of the wire stripping process. When stripping the insulation of the cable 5, the cable is usually introduced in a first step (see fig. 6a) in the direction of the arrows between the open tools, which are currently designed as knives 2ra,2 rb. Once the cable 5 to be stripped is in position, it is fixed with suitable clamps, typically with centering clamps (not shown here). It is likewise conceivable to first fix the cable 5 in a suitable holder and to introduce it between the tools via the holder. At this point the tools 2ra,2rb start to oscillate and the measurement is ready, preferably slightly ahead with respect to the frequency generator. The knives 2ra,2rb move in the direction of the arrows relative to each other (fig. 6b) and start to cut into the non-conductive sheath 5 a. If the cutters 2ra,2rb are too close when moving relative to each other, one or both of the cutters 2ra,2rb contact the electrical conductor 5 b.

As shown in fig. 3 and 5, if the resonant circuit is detuned by such tool conductor contact, the phase S4 and signal U4 suddenly changes from early to late in accordance with the phase shift of the stator-side resonant circuit signal U2S relative to the frequency generator signal U1, so that contact can be detected.

To end the stripping process, after the knife 2r cuts sufficiently deep into the non-conductive sheath 5a, it is typically opened slightly again. The non-conductive sheath 5a is then removed from the electrical conductor 5 b. This is typically done by moving the cutters 2ra,2rb along the longitudinal axis of the electrical conductor 5b relative to the cable 5 (fig. 6c), for example by moving a centering clamp or moving the cutters 2ra,2 rb. Thereby peeling the non-conductive sheath 5a from the electrical conductor 5 b.

Fig. 7a to 7d show a schematic flow of different cross-sections through the conductor 5b and a tangential cutting method for measuring the eccentricity and diameter of the electrical conductor and correcting the eccentricity of the electrical conductor 5b with respect to the axis of rotation. Fig. 7a shows a cross section through the cable 5. In fig. 7a the cable 5 is ideally designed. The cable 5 is composed of a non-conductive sheath 5a and a conductor 5 b. The conductor 5b is arranged coaxially with the non-conductive sheath 5 a. Since the cable is fixed on its sheath coaxially to the rotation axis X, as by centering clamps, not shown here, for its handling, the axis of the conductor 5b coincides with the rotation axis X. The cross-section through the cable 5 in fig. 7a represents an ideal situation. By moving the cutter 2ra rotationally around the conductor 5b towards the axis of rotation X in small steps per revolution, in fig. 7a the cutter 2ra has rotated into cut through the non-conductive sheath 5 a. The cutter 2ra just does not contact the conductor 5 b. Once the cutter 2ra continues to move in the direction of the rotation axis X, the cutter 2ra contacts the conductor 5 b. When the tool 2ra rotates around the conductor 5b in the direction of the arrow, the tool no longer loses contact with the conductor 5b and cuts into the conductor 5b to an equal depth over the entire circumference.

Fig. 7b shows a cross section of a cable 5, which, unlike fig. 7a, is subject to symmetry deviations due to manufacturing conditions and is therefore frequently encountered in practice. The cable 5 in fig. 7b has the same structure as the cable 5 in fig. 7 a. Whereas the conductor 5b is arranged eccentrically with respect to its non-conductive sheath 5 a. During stripping as described in the present case, the tool is rotated in the direction of the arrow about the axis of rotation X (see fig. 7 a). The current rotation axis coincides with the symmetry axis of the non-conductive sheath 5a, but not with the conductor axis L. This means that if the tool 2ra is rotating around the conductor and at the same time is moving towards the axis of rotation X in small steps per revolution, the tool 2ra will first contact the conductor 5b at a point which is the farthest away from the axis of rotation X for making the tool conductor contact. At this point in time, the polar position of the tool 2ra, i.e. the angle on the tool and the distance of the tool 2ra to the rotation axis X, will be read. This corresponds to the first contact radius Rm1 and the first contact angle α m 1.

Fig. 7c shows a cross-section of the cable 5 in fig. 7 b. In fig. 7c, the tool 2ra has been moved further in the direction of the rotation axis X. At the point in time shown in fig. 7c, when the cutter 2ra makes a complete rotation around the conductor 5b, the cutter 2ra comes into contact with the conductor 5 b. This means that the point in time at which there is uninterrupted contact between the tool 2ra and the conductor 5b can be determined, i.e. the point in time at which as large a radial distance as possible between the tool 2ra and the axis of rotation X occurs, in order to achieve continuous tool conductor contact. This corresponds to the second contact radius Rm 2.

The eccentricity vector V may be calculated from the contact radius Rm1, the contact radius Rm2, and the first contact angle α m1 (see fig. 7 d).

Fig. 7d shows a cross-section of the cable 5 of fig. 7b, wherein the eccentricity of the conductor axis L with respect to the axis of rotation X of the cable 5 has been corrected. The cable 5 is moved according to the calculated eccentricity vector V to make the conductor axis L coincide with the rotation axis X. The axis of symmetry of the non-conductive sheath 5a is therefore also offset towards the axis of rotation X according to the eccentricity vector V. With respect to conductor 5b and cutter 2ra, the arrangement now conforms to the ideal layout in fig. 7 a. The cable 5 can be moved by moving a centering clamp or a suitable clamp for clamping or fixing the cable 5.

Fig. 8a to 8b illustrate a crescent-shaped cut, which is another general method for measuring eccentricity, eccentricity vector and radius of a conductor, which was previously described in fig. 7b and 7 c. As with the tangential cutting method shown in fig. 7 b-7 d, the source of eccentricity is irrelevant, whether from the conductor to the cable insulation, from the cable fixture to the axis of rotation, or from the sum of a number of mechanical asymmetries or inconsistencies. In the crescent-cut method, it is also possible to replace the conductor 5b with a metal pin, so that the eccentricity e measured is only related to the eccentricity of the main axis of the cable holding clamp with respect to the rotation axis X. Unlike fig. 7b, fig. 8a shows the conductor 5b and its longitudinal axis only in cross section. As can be seen in fig. 8a, the longitudinal axis L is offset with respect to the rotation axis X. To determine the eccentricity (e) and/or the eccentricity vector (V) and/or the conductor radius (rL), the tool 2ra is moved in the direction of the axis of rotation X while the tool is rotating, as described in fig. 7b, until the tool 2ra contacts the conductor 5 b. The contact forms a first contact radius r1, which corresponds to the radius Rm1 in fig. 7b, and a first contact angle α m1, which in the crescent-cut method is not necessary for determining the eccentricity vector, but can also be measured for plausibility checking. During the rotation of the tool 2ra, the tool 2ra is fed by a certain amount in the direction of the rotation axis X in the next step, and then is spaced apart from the rotation axis X by a second distance. The second distance conforms to a crescent-shaped cutting radius r 2. The crescent cutting radius r2 is chosen appropriately so that for measurement purposes it cuts into the conductor 5b at a crescent cutting angle λ of preferably 120 ° to 200 °. The first crescent cutting contact angle delta represents the angle at which the cutter conductor contact begins at the crescent cutting radius r2 and the last crescent cutting contact angle epsilon represents the angle at which the cutter conductor contact ends at the second cutting radius r2, relative to the selected rotational angle zero. Enclosing a crescent-shaped cutting angle lambda therein. Thus, for the above-mentioned rotation angle zero point, an average contact angle p can be determined which divides the crescent-shaped conductor cut into two symmetrical halves. This average contact angle p of the crescent-shaped cut conforms to the first contact angle α m1 in fig. 7, however the average contact angle ρ of the crescent-shaped cut can be more accurately determined as the average of the first crescent-shaped cut contact angle δ and the last crescent-shaped cut contact angle ε. The average contact angle ρ may also be calculated as the straight center of gravity of the crescent-shaped cut. The eccentricity e and/or the eccentricity vector V can be calculated from the respective data. When the tool crosses the crescent cutting angle lambda, a measurable contact of the tool conductor occurs. The crescent cut angle λ and the average contact angle ρ can be determined from the angles ε and δ, and the conductor radius rL can be calculated according to the geometric relationship as shown in FIG. 8 using the following equation:

therefore, according to fig. 8b, the eccentricity e, the average contact angle p and the eccentricity vector V can also be calculated:

according to the method for measuring eccentricity described in fig. 7c, the cut is made deep into the conductor until the tool and the conductor are in continuous contact. In the above formula for rL, this means that α becomes 180 °. For this limit value, rL becomes:

the results can be viewed graphically from fig. 7c using Rm 1-r 1 and Rm 2-r 2.

The eccentricity vector may also be calculated from the inductance measurement, such as from a coil disposed in the centering clamp. The advantages of this arrangement are: the eccentricity of the conductor axis to the rotation axis can be corrected before lancing.

The coils used to calculate the eccentricity vectors can also be mounted outside the centering jaws, in a separate sensor housing concentric with the axis of rotation X.

Furthermore, the eccentricity vector can also be determined using at least two X-ray diagrams for the perspective of the cable cross-section.

The list of reference numerals and the technical content and illustrations in the patent claims are all part of the patent disclosure. Like reference numerals designate like parts, and reference numerals having different designations designate functionally identical, interrelated, or similar components.

List of reference numerals

lr tool rack

2ra,2rb conductive tool and cutter

3 frequency generator

Electric conductor of 4r rotor side branch circuit

Electric conductor of 4s stator side branch circuit

5 Cable

5a non-conductive sheath

5b electric conductor

6r hollow shaft

7 phase discriminator

10 wire stripping head

11 comparator

12 comparator

13 XOR block

14 low-pass filter

15 intensifier

16D type trigger

17 control device

20 drive device

28 Circuit arrangement

30 drive device

40 electrically insulating layer

41 conductive plate

50 frame

51 fixed plate

100 insulating layer stripper

A rotor side branch circuit

Am U2s amplitude value

B stator side branch circuit

C2r tool capacitor

Conductor capacitor of C4r rotor side branch circuit

Conductor capacitor of C4s stator side branch circuit

Conductor capacitor of C5 cable to be processed

Ca output capacitor

COM communication interface

Ct total capacitance

ECB electric conductor

e eccentricity, distance from axis of rotation to axis of conductor

f frequency

Longitudinal axis of L-shaped conductor

L1 rotor side coil, rotor side inductance element

L2 stator side coil, stator side inductance element

Rm1 first contact radius

Rm2 second contact radius

Rv series resistance

r1 first contact radius

r2 crescent cutting radius

radius of rL conductor

S1 rectangular signal

S2 rectangular signal

S3 rectangular signal, pulse width proportional to phase

S4 signal, digital, phase

Control signal of S5 frequency generator

U1 frequency generator signal

U2s stator side resonant circuit signal

U2r rotor side resonant circuit signal

U4 analog signal proportional to phase shift

V eccentricity vector

X-ray rotation axis

Crescent cutting angle of half alpha

Rotation angle of alpha m cutter (0-360 degree)

First contact angle (0-360 DEG) of am1 cutter

Delta first crescent cutting contact angle

Epsilon Final crescent cut contact Angle

Phi phase shift

Lambda crescent cutting angle

Rho average contact angle

Claims

1. Device for detecting contact with an electrical conductor (5b) by means of at least one electrically conductive tool (2r) rotating around the electrical conductor (5b), in particular a conductor provided with a non-conductive sheath (5a),

comprises that

-a tool holder (1r) rotatably supported about a rotation axis (X), on which tool holder (1r) a tool (2r) is arranged,

-an Electrical Conductor (ECB) arranged on the tool holder (1r), which essentially comprises the tool holder (1r) itself and the hollow shaft (6r) and is electrically insulated with respect to the tool (2r), in particular by an electrically insulating layer (40,40a,40b),

a rotor-side inductive element (L1) arranged on the tool holder (1r) or on the hollow shaft,

-a parallel resonant circuit comprising at least one rotor-side subcircuit (A) and at least one stator-side subcircuit (B),

-a circuit arrangement (28),

a stator-side inductive element (L2),

wherein the rotor-side inductance element (L1) is electrically connected to the tool (2r) via an electrical conductor (4r) at least to the Electrical Conductor (ECB),

and constituting the elements of the rotor-side subcircuit (A) of the parallel resonant circuit,

wherein at least a stator-side inductive element (L2) is arranged in a stator-side subcircuit (B) of the parallel resonant circuit,

wherein the stator-side subcircuit (B) of the parallel resonant circuit is connected to a circuit arrangement (28) by means of an electrical conductor (4S) for detecting a change in at least one typical oscillation parameter (phi, Am, f), in particular the phase (S4) and/or the phase shift (phi) of the parallel resonant circuit,

wherein the parallel resonant circuit has a total capacitance (Ct) which functionally comprises at least a tool capacitance (C2r), characterized in that,

the rotor-side inductive element and the stator-side inductive element are arranged in a suitable manner, in particular spaced apart from one another and preferably not in contact, so that at least one of the typical oscillation parameters (phi, Am, f) of the parallel resonant circuit can be measured independently or in a specific function as a function of the rotational speed of the tool holder (1r) relative to the circuit arrangement.

2. Arrangement according to claim 1, characterized in that the rotor-side and stator-side inductive elements are designed as coils (L1, L2), which coils (L1, L2) are inductively coupled to each other.

3. Device according to claim 1 or 2, characterized in that the rotor-side and stator-side inductive elements are arranged coaxially with the rotational axis (X) of the tool holder (1r) and that the rotor-side and stator-side inductive elements at least partly overlap in the axial direction.

4. A device according to any one of claims 1 to 3, characterized in that the stator-side inductive element is designed as a ring coil and the rotor-side inductive element for the ring coil is likewise designed as a coaxial ring coil, wherein the two ring coils at least partially overlap.

5. The apparatus of claim 4 wherein the toroids completely overlap each other.

6. Device according to any of claims 2 to 4, characterized in that the rotor-side and stator-side inductive elements are of cylindrical or plane-parallel design and are coaxial with the axis of rotation (X) of the tool holder (1 r).

7. A device according to any one of claims 2-6, characterized in that the rotor-side and/or stator-side inductive elements are designed as spiral tracks of windings or electrical conductors on a non-conducting and non-magnetic material.

8. The device according to one of claims 2 to 6, characterized in that the rotor-side and/or stator-side inductive elements have ferromagnetic material, in particular for improving the inductive coupling.

9. Arrangement according to one of claims 1 to 8, characterized in that the rotor-side and/or stator-side inductive elements are designed as single-or multi-layer coils (L1, L2).

10. Device according to any one of claims 1 to 9, characterized in that the tool (2r) is embedded between two electrically conductive plates (41) which are electrically connected to the rotor-side inductive element (L1) by means of an electrical conductor (4r) and are electrically insulated from the Electrical Conductor (ECB) by means of an electrically insulating layer (40a, 40 b).

11. Device according to any one of claims 1 to 9, characterized in that the tool (2r) is connected to the rotor-side inductive element (L1) by at least one electrical sliding contact consisting of an electrically conductive plate (41) and by an electrical conductor (4 r).

12. Machine for insulation stripping provided with at least one stripping blade (2r) as tool, which is held by a tool holder rotatably supported about a rotation axis and to which at least one device for detecting contact with an electrical conductor (5b) of a cable (5) according to any one of claims 1 to 11 is connected, wherein the device is connected to at least one tool (2ra,2 rb).

13. Method for detecting contact with an electrical conductor (5b) by means of at least one electrically conductive tool (2r) rotating around the electrical conductor (5b), in particular a conductor provided with a non-conductive sheath (5a), for which purpose a device, in particular a device according to one of claims 1 to 11, or an insulation stripper according to claim 12 is used,

the device comprises

-an Electrical Conductor (ECB) arranged on the tool holder (1r), which in this case essentially comprises the tool holder (1r) itself and the hollow shaft (6r) and is electrically insulated with respect to the tool (2r), in particular by an electrically insulating layer (40,40a,40b),

-a rotor-side inductive element (L1) arranged on the tool holder (1r) or on the hollow shaft

-a fixed circuit arrangement (28),

a stator-side inductive element (L2),

wherein the parallel resonant circuit has a total capacitance (Ct) functionally comprising at least a tool capacitance (C2r) by:

-setting the frequency generator signal in a range of resonance frequencies, preferably below the resonance frequency of the parallel resonant circuit, according to the defined sensitivity

-measuring at least one typical oscillation parameter (Φ, Am, f) of the parallel resonant circuit and determining the limit values of the contact of the tool (2ra,2rb) with the conductor (5b)

-arranging a rotary tool holder (1r) relative to a fixed circuit

-continuously measuring at least the typical oscillation parameters (Φ, Am, f), in particular the phase S4 and/or the phase shift (Φ), of the parallel resonant circuit and comparing these measurements with one or more limit values determined by means of standard measurements in order to detect the contact of the conductor (5b) with the tool (2ra,2 rb).

14. Method according to claim 13, characterized in that a signal is output when a limit value is reached, in which case it is advantageous to use the signal for controlling at least one function of the device.

15. The method according to claim 13 or 14, characterized in that the circuit arrangement (7) evaluates the phase (S4) and/or the phase shift (Φ) between the stator-side resonance circuit signal (U2S) and the frequency generator signal (U1).

16. Method according to claims 13 to 15, characterized in that the point in time when the tool (2r) touches the conductor (5b) and the duration of time when the tool (2r) touches the conductor (5b) are recorded as separate parameters and that the correspondingly processed electrical conductors are preferably sorted on the basis of these parameters.

17. Method according to claims 13 to 16, characterized in that the position of the tool (2r) in contact with the conductor (5b) in the direction of the axis of rotation (X) is recorded as individual parameters and the correspondingly treated electrical conductors are preferably sorted on the basis of these parameters.

18. Method according to claims 13 to 17, characterized in that the position of the tool is recorded, in particular continuously recorded, and the cable diameter is determined from the tool opening for the point in time when the tool (2r) touches the conductor (5 b).

19. Method according to claims 14 to 18, characterized in that the angular position (am), in particular continuously, of (on) the monitored tool or tools (2ra,2rb) relative to the axis of rotation (X) is recorded.

20. Method according to claim 19, characterized in that the distance of the tool (2ra) to the axis of rotation (X) is reduced until a first tangential contact with the conductor (5b) by the tool (2ra) is made, and the angular position (α m1) of the tool (2ra) and the tool (2ra) position are saved, wherein the tool (2ra) position corresponds to the relevant first contact radius (Rm1, r 1).

21. Method according to claim 20, characterized in that the distance of the tool (2ra) to the axis of rotation (X) is further reduced until the tool (2ra) is continuously in contact with the conductor during one complete revolution of the tool (2ra) around the conductor (5b), and the position of the tool (2ra) is saved as the second contact radius (Rm 2).

22. The method of claim 21, wherein the eccentricity vector (V) is calculated using the first and second contact radii (Rm1, Rm2) and the angular position (am 1).

23. Method according to claim 19, characterized in that the distance of the tool (2ra) to the axis of rotation (X) is reduced until a first tangential contact with the conductor (5b) by the tool (2ra) is made and is stored as a first contact radius (Rm1, r1), and in that the distance of the tool (2ra) to the axis of rotation (X) is also reduced to a crescent cutting radius (r2) until the tool (2ra) contacts the conductor (5b) at an angle of preferably 120 ° to 200 ° on the circumference, wherein the start of the contact is stored as a first crescent cutting contact angle (δ) and the end of the contact is stored as a last crescent cutting contact angle (ε).

24. Method according to claim 23, characterized in that the conductor radius (rL) and/or eccentricity (e) and/or eccentricity vector (V) is calculated using the first contact radius (r1), the crescent cutting radius (r2), the first crescent cutting contact angle (δ) and the last crescent cutting contact angle (ε).

25. Method according to claim 22 or 24, characterized in that the eccentricity is compensated by moving the conductor (5b) relative to the axis of rotation (X) according to an eccentricity vector (V).

26. Method according to any of claims 18 to 25, wherein the electrical conductor (5b) is a conductive layer of a coaxial or triaxial cable, wherein these steps are repeated for each layer of the coaxial or triaxial cable, thereby determining the diameter and/or eccentricity vector (V) of each conductive layer.

27. Method according to claims 16 to 26, characterized in that for each tool (2ra,2rb) the point in time when the tool (2ra,2rb) touches the conductor (5b) and the duration of time when the tool (2ra,2rb) touches the conductor (5b) are recorded separately.

28. Method according to claims 27 and 20, characterized in that a respective contact diameter (Rm1) is calculated for each tool (2ra,2rb) so as to enable radial adjustment of the tool (2ra,2rb) with respect to the rotation axis (X) so as to leave each tool (2ra,2rb) at the same distance from the rotation axis (X).